Locomotive fire-box



(No Model.)

W. MALAM. LOOOMOTIVE FIRE BOX.

No. 417,059. Patented Dec. 10, 1889.

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mam/w M PETERS, Phnto-Lilhogrzphcr, Whhmglon, ll C.

UNITED STATES,

PATENT OFFICE.

\VILTJAM MALAM, OF EDGEMOOR, DELAXVARE.

LOCOMOTIVE FIRE-BOX.

SPECIFICATION forming part of Letters Patent No. 417,059, dated December10, 1889. Application filed November 1, 1888. Serial No. 289,719. (Nomodel.)

To all whom it may concern.-

Be it known that 1, WILLIAM MALAM, a subject of the Queen of GreatBritain and Ireland, residing at Edgemoor, New Castle county, Delaware,have invented certain linprovements in Locomotive Fire-Boxes, of whichthe following is a specification.

One object of my invention is to so construct a corrugated crown-sheetfor the firebox of a boiler of the locomotive typethat pressure upon thecrown-sheet will not cause any other than a direct vertical strain uponthe side sheets of the fire-boxor upon the joint formed between theupper edges of the side sheets and the flanges of the crownsheet, afurther object being to so form the corrugated crown-sheet as to insurethe best heating effect.

In the accompanying drawings, Figure 1 is a longitudinal section ofsufficient of a boiler of the locomotive type to illustrate myinvention- Fig. 2 is a transverse section on the line 1 2, Fig. 1. Fig.3 is a section of part of the fire-box casing on a still larger scale,and Fig.4 is a similar view on a smaller scale and illustrating anotherform of firebox to which my invention may be applied.

A represents part of the outer shell or casing of the boiler; 13, therear sheet of the firebox; D, the front or tube sheet; E, the tubes; FF, the opposite side sheets of the fire-box, and G the crown-sheet,which is corrugated transversely, so as to impart to it such rigidity aswill render unnecessary the employment of the usual crown-bars and staysfor the crown-sheet.

In the boiler shown in Figs. 1 and the crown-sheethas at each side avertical flange a, which is riveted to the upper edge of the side sheetF of the fire-box, and the corrugations in the crown-sheet are carriedout full to these flanges, so that throughout'the entire length of thecrown-sheet-that is to say, from the front end to the rear end of thesame-the ends of the corrugations are in the same vertical planes as thesides of the fire-box. By this means the rigidity of the crown-sheet,due to the corrugating of the same, is maintained up to the very edgesof the sheet; hence there is no weakening of the sheet at or near theedges, so that the pressure upon the crown-sheet is transmitted to theside sheets of the fire-box in a true vertical plane, or in a directiontransversely to the axes of the rivets. The separation of thecrown-sheet from the sides of the firebox will thus necessitate theactual shearing off of these rivets, and accidental rupture or strainingof the joint is rendered extremely improbable. The opposite flanges a ofthe crown-sheet preferably follow the corrugated contour of the same, sothat a longer line of rivets can be used for securing the crownsheet andside sheets of the fire-box than if the flange and securing line ofrivets were straight. A straight flange and straight line of rivets may,however, be employed without departing from my invention. (See Fig. 3,for instance.)

It will be observed, on reference to Fig. 1, that the depth of thecorrugations in the crown-sheet gradually increases from the rear to thefront of the firebox-that is to say, the shallowest corrugation isadjacent to the rear plate 13 of the fire-box, and the deepestcorrugation is adjacent to the flue-sheet D of the sameso that thedeeper corrugations and the greater surface exposed to the action of theproducts of combustion are me sented at those points where the productsof combustion are hottest.

In carrying out my invention, however, it is not absolutely necessarythat the corrugations should be graduated nor that the crownsheet shouldbe separate from the side plates of the fire-box; and in Fig. 4 I haveshown an instance in which the crown-sheet and side plates are in onepiece, this structure, however, showing the essential feature of theinvention that is to say, the carrying of the corrugations of thecrown-sheet fully out to the edges of the same, so that the ends of saidcorrugations shall be in the same plane as the side sheets of thefire-box.

Although the crown-sheet shown is in one piece extending from front torear of the fire-box, it may in long fire-boxes be composed of severalsections suitably secured together. It is advisable, however, in allcases to make the crown-sheet continuous from side to side of thefire-box; but the sheet may in some cases be arched transversely, asshown by dotted lines in Fig. 2, for instance.

Having thus described my invention, I claim and desire to secure byLetters Patent 1. The combination, in a locomotive firebox, of the sidesheets and a transverselycorrugated crown-sheet having the corruga-vtions carried out full to the ends of the sheet and sides of the box,the ends of the corrugations being in the same plane as the sides of thefire-box, substantially as specified.

2. The combination, in a locomotive firebox, of the side sheets andtransversely-corrugated crown-sheet, the corrugations of the crown-sheetincreasing in depth from the rear to the front of the fire-box and beingcarried out full to the ends of the crownsheet and sides of the box,whereby the ends of the corrugations are in the same plane as the sidesof the fire-box, substantially as specified.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing Witnesses.

WILLIAM D. CONNER, 4 HARRY SMITH.

